Installing on Mac-formatted iPod

I'm trying to install Rockbox 3.7.1 on a Mac-formatted iPod Nano
(second gen). Doesn't work because Linux cannot write to this
particular filesystem (HFS+, case insensitive, journaled -- i.e. the
Mac default filesystem). I previously worked around this on a first
gen nano by borrowing a friend's windows machine, installing iTunes,
and reformatting the older iPod. What a PITA! I'd like to avoid all
that fuss on the newer iPod.

Suggestions? I.e. is there a way to reformat an iPod Nano to
"Windows" format without needing iTunes on Windows? (I have easy
access to multiple Linux boxes and Macs, but not Windows.)